This invention relates to apparatus for preparing and dispensing beverages wherein one of a plurality of drink concentrates and cooled fresh water enriched with CO.sub.2 gas, and forming carbonated water thereby, are brought together in a predetermined ratio for preparing a selected type of a carbonated beverage and where the fresh water is blended with CO.sub.2 gas in a cooled storage tank, referred to as a carbonator, that is refilled from a source of water by a pressure pump and a water level controlled intake valve.
Apparatus for mixing fresh water with CO.sub.2 gas to produce carbonated water is well known and is used, for example, in post-mix beverage dispensing machines so that carbonated beverages can be prepared and dispensed on demand by mixing carbonated water with a suitable drink concentrate. As noted above, the carbonated water mixed with the drink concentrate is produced directly in the storage tank or carbonator. The carbonator is normally fed fresh water of drinking quality either from a pressurized water line; however, it can be supplied from a pressurized storage tank. A nonreturn check valve is located in the feed line to prevent a return flow. Further, CO.sub.2 gas is fed to the carbonator from a CO.sub.2 gas storage tank by a pressure-reducing regulating valve so that a pressure of, for example, about 4 bars is built up in the carbonator.
In order to ensure sufficient carbonation of the fresh water, the carbonation process is accomplished by or assisted by the use of a circulating pump located in the carbonator. This type of pump draws CO.sub.2 gas from the upper or head-space region of the carbonator filled with CO.sub.2 gas and blends it with circulating water which is set in circular motion, such as by spinning.
Cooling of the carbonator is used, not only to improve the carbonation, but also as a requirement so that the finally prepared and dispensed drink exhibits a desired low and basically constant temperature. The cooling in the carbonator is achieved by a cooling system, which is adapted to form an ice bank or layer of generally uniform thickness along the inner side walls of the carbonator as a result of the circulating water. Consequently, a cooling capacitor is produced, thus enhancing its "refrigerating capacity", thereby removing the need for a relatively powerful cooling system which would be necessary in a once-through cooling system.
When a freshly prepared beverage of a certain type is desired, a valve is opened in an output line connected to the bottom area of the carbonator, whereupon cooled carbonated water, metered by a flow-volume regulating valve, is fed to a mixing station to which a correspondingly metered amount of a selected drink concentrate is also fed. To provide a possibility of selection among several concentrates, the carbonated water is individually fed to a dispensing point of the individual concentrate or conveyed past all dispensing points in succession for example, by a mixing station. The bringing-together of different concentrates at one and the same mixing point is somewhat more complicated.
It may also be desirable to prepare and dispense beverages without CO.sub.2 content in addition to beverages with CO.sub.2 content. So that beverages made with fresh or uncarbonated water can be provided, it becomes desirable that cooled fresh water also be delivered to the mixing station. Conventional apparatus typically includes a separate cooled fresh water storage tank and associated apparatus.